Gut Microbiome Dysbiosis and Its Association with Malnutrition in Under-Five Children in Sokoto State: A Comparative Analysis

Emerging evidence implicates gut microbiome dysbiosis as both a consequence and a driver of childhood malnutrition, with disrupted microbial ecology compromising nutrient absorption, immune development, and growth trajectories. This comparative cross-sectional study characterized gut microbiome composition in malnourished versus well-nourished under-five children at Usmanu Danfodiyo University Teaching Hospital, Sokoto State, in the North West geopolitical zone of Nigeria. Forty severely malnourished children diagnosed with either kwashiorkor or marasmus were matched by age and sex with 40 healthy controls. Stool DNA was extracted and 16S rRNA gene amplicon sequencing targeting the V3-V4 hypervariable region was performed on an Illumina MiSeq platform. Alpha and beta diversity indices were computed. Malnourished children demonstrated significantly reduced alpha diversity compared to controls (Shannon index 2.8 versus 4.1, p < 0.001). Relative abundance of Bifidobacterium and Lactobacillus were markedly reduced in the malnourished group. Enterobacteriaceae and Clostridiaceae were disproportionately enriched in the dysbiotic gut microbiome of malnourished children. Functional metagenomics predicted impaired short-chain fatty acid production pathways in the malnourished group. These findings demonstrate a distinct dysbiotic gut signature in severely malnourished Sokoto children and provide a scientific rationale for microbiome-targeted interventions including synbiotic supplementation as adjunctive therapy in malnutrition management. Keywords: gut microbiome, dysbiosis, malnutrition, under-five children, Sokoto.